Summer elk calf survival in a partially migratory population
Summer elk calf survival in a partially migratory population
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夏季麋鹿幼崽在部分迁徙种群中的生存
DOI：
10.1002/jwmg.22330
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
E. Merrill
中科院分区：
文献类型：
--
作者：
J. Berg;D. Eacker;M. Hebblewhite;E. Merrill
分解变异的少年招募是了解种群动态的一个关键组成部分，部分迁徙有蹄类动物。我们调查了成年雌性麋鹿（Cervus canadensis）的生殖参数，以及2013年至2016年在加拿大阿尔伯塔部分迁徙麋鹿种群中小牛的存活率，原因特异性死亡率以及影响小牛死亡风险的内在和外在因素。与移民小牛相比，居民母亲所生的麋鹿小牛平均存活率低45%（0.24比0.69），死亡率几乎是熊（熊属）的两倍（0.37比0.19），死亡率的主要来源。与我们的预测相反，我们发现母体无摄入体脂肪水平的增加与小牛死亡风险的增加有关，这表明捕食可能具有压倒性的营养作用。我们没有发现任何证据表明小牛出生的时间或出生体重在迁徙策略之间存在差异或影响死亡风险。我们发现，随着砍伐森林比例的增加，幼鹿死亡的风险略有下降，这使移民麋鹿受益，与居民相比，他们暴露于更多的皆伐。暴露熊捕食风险是不重要的隐藏阶段（出生后≤10天）的迁移策略，可能是因为新生儿隐藏行为降低脆弱性。与此相反，熊捕食风险是重要的死亡风险后10天的年龄，特别是居民麋鹿小牛，这是暴露于更高的熊捕食风险相比，移民。我们的结论是，熊捕食迁移策略之间的相对差异，通过对小牛死亡率的加性效应，在这个人口的动态部分迁移。因此，野生动物管理者应该预料到，恢复灰熊（美国）。arctos）种群可能会通过影响夏季幼仔的存活率，大大降低麋鹿的招募，特别是在各种食肉动物聚集的地区。
Decomposing variation in juvenile recruitment is a key component of understanding population dynamics for partially migratory ungulates. We investigated reproductive parameters of adult female elk (Cervus canadensis) with calves at heel, and survivorship, cause‐specific mortality, and intrinsic and extrinsic factors affecting risk of mortality for calves in a partially migratory elk population from 2013–2016 in Alberta, Canada. Elk calves born to resident mothers had 45% lower survivorship on average compared to migrant calves (0.24 vs. 0.69) and nearly twice the mortality rate (0.37 vs. 0.19) from bears (Ursusspp.), the dominant source of mortality. Contrary to our predictions, we found that increasing levels of maternal ingesta‐free body fat were associated with increasing risk of calf mortality, indicating predation may have overwhelmed nutritional effects. We found no evidence that timing of calf birth or birth weight differed between migratory tactics or influenced mortality risk. We found that as percentage of cut forest increased, risk of calf mortality marginally decreased, which benefited migrant elk that were exposed to more clear‐cuts compared to residents. Exposure to bear predation risk was unimportant during the hiding phase (≤10 days after birth) for either migratory tactic, presumably because neonatal hiding behavior reduced vulnerability. In contrast, bear predation risk was important for mortality risk after 10 days in age, especially for resident elk calves, which were exposed to higher bear predation risk compared to migrants. We conclude that relative differences in bear predation between migratory tactics are contributing to the dynamics of partial migration in this population through additive effects on calf mortality. Thus, wildlife managers should anticipate that recovering grizzly bear (U. arctos) populations may substantially lower elk recruitment through effects on summer calf survival, especially in areas with diverse carnivore assemblages.
影响因子：
4.8
作者：
通讯作者：
--
影响因子：
3
作者：
Merrill，Evelyn;Killeen，Joshua;Hebblewhite，Mark
通讯作者：
Hebblewhite，Mark